There has been known a sheet transport device configured to read an image on a sheet using a reading unit while transporting the sheet along a predetermined transport path (for example, refer to JP-A-2011-211480).
The sheet transport device disclosed in JP-A-2011-211480 includes a U-turn transport path disposed in a middle portion of the transport path from a sheet feed side to a sheet discharge side. The sheet transport device includes, in the U-turn transport path, a main roller which transports and guides the sheet to U-turn the sheet, and a pinch roller which is arranged to face an upper portion of the main roller during the transport of the sheet and transports the sheet together with the main roller.
The sheet transport device further includes a cover member which covers the main roller from above and opens at least a portion of the transport path from above when maintenance is performed or jamming occurs. The pinch roller is supported by a rear surface of the cover member. Also, a shaft of the pinch roller does not necessarily have to receive driving since only the pinch roller is rotated by the driving of the main roller. Therefore, the shaft of the pinch roller is fixed to the rear surface of the cover member by, for example, fitting using the elastic deformation of a rib formed on the rear surface of the cover member.
This kind of sheet transport device is demanded to be made thinner and the cover member is demanded to be made thinner. Accordingly, the height of the rib which supports the shaft of the pinch roller is required to be reduced.
However, this type of rib is integrally formed on the rear surface of the cover member by resin forming, and thus it is difficult to reduce the height of the rib without limitation to make the cover member thin. In other words, as described above, the shaft of the pinch roller is fixed by using the elastic deformation of the rib, and the amount of elastic deformation becomes insufficient when the height of the rib is excessively reduced and the operation becomes difficult when the shaft is attached. Also, in some cases, there is a possibility that the rib wound be damaged.